CurtPalme.com Home Theater Forum

[KrisRoberts]

A few weeks ago I started playing with HCFR and a Spyder2. It was fun, and after a couple evenings I felt like I had significantly improved the color/greyscale on my G90. Joy.

But I was sad about the lack of low light resolution on the Spyder and decided to order an EyeOne Display LT probe.

So far I've been completely frustrated trying to use the EyeOne.

With the spyder I could face it towards the projector and get what seemed like pretty good readings. I tried turning it from one side and then the other and dont see that much red/blue bias based on the orientation. But with the EyeOne if it is facing the projector it gets wildly different red and blue values with even slight changes in orientation.

So fine, I've also been told to point it at the screen to minimize that. But when I setup a new file in HCFR it wants to 'calibrate' the EyeOne with a white field. So far no matter what I've tried I can not get it to calibrate facing the screen. It always responds with an error saying that it cant detect the crt refresh rate.

I tried the suggestion of making a little baffle out of half a toilet paper tube painted black to keep it from seeing its shadow. I've tried pointing it off to one side, up and down and different distances from the screen. But nothing seems to make it happy.

If I calibrate it pointed at the projector and then try to use it pointed at the screen the results I get are hard to trust.

Did I maybe get a bum probe, or is there something obvious I'm missing? Have others used this probe with HCFR on their CRT projectors with good results?

[GEBrown]

I think you should be using the LCD setting and not the CRT setting for our projectors.

I ran into the same problem when trying to use the CRT setting. Remember that the software is supposing that you've got the sensor mounted directly on the screen, not 8 or so feet away.

I got pretty good results aiming it at the screen and selecting LCD.

Now, what I'd be interested in hearing you try is the following.

Put up a 20 or 30 IRE window on your projector, then select "Continuous Measures" from the HCFR software. When I do that, the measurement screen never advances. If I put up a 40 IRE or higher window, then that function works as usual.

Hope this Helps

Gary

[WTS]

I would think if it never advances then it hasn't gotten a sufficient reading to allow it to move on to the next reading. I use the HCFR probe facing the screen and I can reading at 10ire.

[GEBrown]

[WTS]

No I bought it from dlarsen over on AVS, it wasn't worth it for me to just build one for myself. I don't know if he has anymore left as I bought it about 3 months ago. I think I saw someone else overthere doing boards for the probe though.

[garyfritz]

FWIW I can read 10ire off the *screen* with my (formerly Gary's ) SpyderII. I'm amazed the Display LT can't do it...?? Doesn't it have options to take longer exposures?

[GEBrown]

[garyfritz]

I don't know if the SpyderII will do Continuous Measures at 10IRE. Probably not. But I don't care, because I never do it! I set grayscale at 30% and 80%. So as long as the Spyder can read continuous off the screen at 30% (IRE30), I'm happy. Then it just takes a longer exposure at 10% and 20% and it's happy too. Everybody happy!

Happy now?

[Andrew Low]

[GEBrown]

Hopefully Gary Fritz will chime in here as well:

When you calibrate a display, you are trying to balance the primary colors for all levels of brightness. A colorimeter sensor allows you to do this. The most common method is to pick two IRE levels, say 30 and 80, and adjust the G2 levels for the IRE 30 level and the drive levels for the 80 IRE window.

Adjusting G2's has little or no effect on bright/near white scenes.

So, the HCFR "Continuous Measures" allows us to pull up a 20 or 30 IRE test window from a calibration DVD and continously display the G2 level for each color as it relates to the target light color (usually 65k degrees Kelvin). We can adjust the G2's for the individual primaries and see how close they are to the ideal curve.

Then you usually bring up an 80 IRE test window and adjust the primaries using the "drive" controls.

Finally you can use your colorimeter software to measure your grayscale from 0 through 100 IRE.

End of babble.

[loribates]

[JustGreg]

I agree Lori. I learned more in this one post than I have in the 2 years I've owned my Marquee. This subject just doesn't come up or hang around long enough for us slow learners to get a grasp on it so I eyeball it and call it good.

I don't think the wife is going to spring for a colorimeter for Christmas tho. It's cheaper for me to just get new glasses every year and I don't have a honeydo list that grows proportionately to the price of the toys I buy.

Greg

EDIT:Hey Kal, Curt. I just thought of something. Would it be possible or profitable for you to buy a colorimeter and rent it to us? I'm personally not the kind of person who would have need of one hanging around in the CRT toolbox so renting would be a very cool option for occassional use. Does that sound do-able Curt? I'm assuming of course that it will be treated well and returned on time by the renter...there's always one that ruins it for many but maybe it's something worth thinking about.

[AnalogRocks]

[AnalogRocks]

[GEBrown]

[loribates]

Well, your post finally turned the light on for me about how the drive and g2 work. Thank you very much! Now I guess I need better equipment to calibrate from because the results I got tonight pretty much sucked..... you can read about that in the thread where I was asking for help with this issue..... still..... I'm much more enlightened about how this should work once I get my hands on a better sensor..

[David_Web]

Interesting!

Do you think a lux/photometer could be used to calibrate a display?

Another ting that bugs me. What do the numbers measured in HCFR mean?
I get xyz as coordinates on the color table but what is the unit for the numbers marked RGB?
for example in the 0-100IRE window.

Imputing the data manually would suffice as I have access to some very good lux meters that can also do luminance.
And soon also a spectrometer. Would be interesting to see what a CRT spits out.

[garyfritz]

Lori, see this post over on the A site. It might help you understand the gray-scale calibration process even better.

David, I think a lux meter or photometer just measures light levels, yes? So it doesn't give you any readings of the exact color temperature. That might help you measure your overall gamma curve, but not the grayscale. You really want something that will return the x/y coordinates on the CIE diagram, where 6500K is a 0.313 / 0.329. A spectrometer might do that -- I'm not sure.

Coordinates: there are many different color coordinate systems. xyz is one, but xyY is what you want for measuring grayscale. The x/y coords are CIE coords, and the Y value is light intensity -- measured in cd/m^2 (metric unit) in HCFR. Some people use foot-Lamberts (English unit) instead. 1 ftL = 3.426 cd/m^2.

[Nashou66]

This post is an old one but I want to let people know how the Eye One Display 2LT should be used. In this thread I show different configuratios for the eye one and compared. To Calibrate the Eye One for CRT use you set HCFR for LCD then when you are asked to calibrate Eye One after selecting continuous measure just place the probe on a flat surface so the foam "gasket" blocks all light to the sensor. once this is done you can place your Eye one with the most convenient
Placement and start calibrating. its a very nice probe and gets good measures at 10 IRE and even @ 5 IRE, with 0 IRE you get no error but i dont thing the reading is very accutate, I am getting a spyder 2( said not to be as consistently manufactured) to compare and will add that to the first post of the posted thread below.

Eye One Display2LT Different Trials

Athanasios

[kal]

[kal]

[Nashou66]